ABSTRACT: The present study was conducted during the two consecutive seasons 2018 and 2019 on “Crimson
Seedless” table grapes to mitigate the excessive ProTon concentration by some cytokinin use. The following
treatments were used: control, thidiazuron at 50ppm (TDZ), abscisic acid at 250ppm (ABA) preceded by TDZ at
50ppm, ABA at 500ppm preceded by TDZ at 50ppm, benzyl adenine at 50ppm (6-BA), ABA at 250ppm preceded
by 6-BA at 50ppm, ABA at 500ppm preceded by 6-BA at 50ppm, ABA at 250ppm and ABA at 500ppm.Treatment
of TDZ and 6-BA were applied at berry set while ABA treatment was applied at 10-15% berry coloration. The
results showed that pre-harvest application of TDZ or 6-BA increased cluster weight, 100 berry weight, pedicel
weight, berry acidity, berry and leaves chlorophylls and decreased berry coloration, TSS, total sugars. The
application of ABA at 10-15% berry coloration enhanced berry anthocyanin content, TSS, Total sugars and
lowered acidity and chlorophyll. The present study recommended using either TDZ or 6-BA at 50ppm followed
by ProTon at 500ppm to mitigate the excessive ProTon concentration on “Crimson Seedless” grapes.
